Preparation of substituted quinones



Patented Oct. 30, 1951 PREPARATION OF SUBSTITUTED QUINONES William K. T. Gleim, Orland Park, and Alexander Gaydasch, Brookfield, Ill., assignors to Universal Oil Products Company, Chicago, 111., a corporation of Delaware No Drawing. Application September 8, 1949, Serial No. 114,688

12 Claims.

This invention relates to a process for preparing substituted quinones and particularly for preparing mono-substituted para-benzoquinones.

An object of this invention is to prepare a quinone having a hydrocarbon substituent attached to the quinone ring.

Another object of this invention is to produce an alkyl quinone.

A further object of this invention is to produce Z-tert-butylquinone.

A still further object of this invention is to produce 2,5-di-t-butylquinone.

One specific embodiment of this invention relates to a process for producing a substituted quinone which comprises oxidizing a mono-ether of a substituted hydroquinone.

Another embodiment of this invention relates to a process for producing an alkyl substituted quinone which comprises oxidizing a monoalkyl ether of a substituted hydroquinone having a hydrocarbon substituent combined with the hydroquinone ring.

A further embodiment of this invention relates to a process for producing a tertiary butylquinone which comprises oxidizing a monoalkylether of a tertiary butylhydroquinone.

A still further embodiment of this invention relates to a process for producing 2-tertiarybutylquinone which comprises oxidizing 2-tertiary-butyl-4-methoxypheno1.

An additional embodiment of this invention relates to a process for producing 2,5-di-tertbutylquinone which comprises oxidizing 2,5-ditert-butyl-4-methoxyphenol.

Heretofore it has been found difficult to produce substituted quinones and especially to produce mono-substituted benzoquinone. We have found unexpectedly that mono-ethers of hydroquinones having a hydrocarbon substituent bound to the hydroquinone ring are oxidized to to the corresponding quinones when employing oxidizing agents comprising alkali chlorate and vanadium pentoxide and also nitrous acid and sodium nitrite.

This method is particularly advantageous in the preparation of monoalkylquinones, as it is much easier to monoalkylate 4-methoxyphenol than it is to produce monoalkylhydroquinone from hydroquinone itself.

In carrying out this process, a monoalkylether of hydroquinone such as 4-methoxyphenol, 2- tert butyll-methoxyphenol and 2,5-di-tertbutyl-l-methoxyphenol is placed in a suitable reactor together with dilute sulfuric acid and an oxidizing catalyst such as vanadium pentoxide,

and an oxidizing agent such as potassium chlorate, or sodium nitrite is added slowly while the reaction temperature is kept at a temperature of between about -l0 to about C.

During this oxidation treatment, the reaction mixture is stirred vigorously, for example, by a motor driven stirrer or by other suitable means. When the oxidation is complete, the reaction mixture is cooled, the crude quinone layer is separated and purified either by recrystallization or steam distillation. The crude quinone which is obtained in a yield of from about 50 to about 90% is then recrystallized generally from alcohol to efiect further purification.

The nature of the present invention and type of results obtained are indicated by the following examples, although the data presented therein should not be misconstrued to limit unduly the broad scope of the invention.

Example I Tertiary butylquinone was produced in one run by the following procedure: 90 grams /2 mole) 2-t-butyl-4-methoxyphenol was suspended in 150 cc. 1120 at 47", then 10 grams concentrated H2SO and 0.5 grams V205 were added with vigorous stirring. A solution of 0.2 mol KClOz in cc. B20 was added slowly in such a way as to keep the temperature at 50. After all of the chlorate solution was added the reaction mixture was, stirred for one hour at 47. When the reaction mixture has cooled, the crude quinone layer was separated in a separating funnel, and steam distilled while adding about 5 grams CaCOs. The yield was about 45 grams of crude quinone (55% yield) which when recrystallized from alcohol, yielded yellow needles, of M. P. 59.

Two grams of this material was hydrogenated at room temperature under 60 lbs. H2 pressure with 2 grams of Ni hydrogenation catalyst. Crystals of M. P. 126127 were obtained. This material did not give depression in a mixed M. P. with authentic Z-t-butyl-hydroquinone of M. P. 125-427".

Example II In another run, tertiary butylquinone was prepared as follows: Thirty-three grams Z-t-butyl- -methoxy-phenol was dissolved in 50 grams methanol, and 10 grams concentrated H2804 was added. This mixture was stirred vigorously and cooled to +5". A solution of 15 grams NaNOz in 25 cc. H2O was added slowly. The temperature was not permitted to exceed 10. After about one hour, the reaction was 3 terminated by the addition of 1 gram urea and the whole mixture was steam-distilled. A gram yield of tertiary butyl quinone was obtained, this being equivalent to 66% of the theoretical yield.

Example III 2,5-di-tertiary butylquinone was prepared as follows: Twelve grams, 2,5-di-t-buty1-4-methoxyphenol was dissolved in 100 grams CH3OH. Seven grams powdered NaNOz was added while stirring vigorously. A solution of 6 grams concentrated H2504 in cc. H2O was added dropwise. The temperature increased from 20 and 24. When fumes of N02 started to appear, the reaction was terminated by addition of 1 gram of urea. The reaction mixture was filtered from 10.9 grams di-t-butylquinone M. P. 150. Total reaction time about hour, yield 93%.

We claim as our invention:

1. A process for producing a quinone having a hydrocarbon substituent on the quinone ring which comprises oxidizing a monoether of a hydroquinone in the presence of an oxidizing agent selected from the group consisting of alkali chlorate, vanadium pentoxide, nitrous acid and sodium nitrite.

2. A process for producing an alkyl quinone which comprises oxidizing a monoalkyl ether of a hydroquinone having a hydrocarbon substituent combined with the hydroquinone rin in the presence of an oxidizing agent selected from the group consisting of alkali chlorate, vanadium pentoxide, nitrous acid and sodium nitrite.

3. A process for producing a tertiary butylquinone which comprises oxidizing a monoalkylether of a tertiary butylquinone in the presence of an oxidizing agent selected from the group consisting of alkali chlorate, vanadium pentoxide, nitrous acid and sodium nitrite.

4. A process for producing Z-tertiary-butylquinone which comprises oxidizing 2-tertiarybutyl--methoxyphenol in the presence of an oxidizing agent selected from the group consisting of alkali chlorate, vanadium pentoxide, nitrous acid and sodium nitrite.

5. A process for producing 2,5-di-tert-butylquinone which comprises oxidizing 2,5-di-tertbutyl-4-methoxyphenol in the presence of an oxidizin agent selected from the group consisting of alkali chlorate, vanadium pentoxide, nitrous acid and sodium nitrite.

6. A process for producing a quinone having a hydrocarbon substituent on the quinone ring which comprises oxidizing a monoether of a hydroquinone at a temperature of from about -10 to about C. in the presence of an oxidizing agent selected from the group consisting of alkali chlorate, vanadium pentoxide, nitrous acid and sodium nitrite.

I. A process for producing 2-tertiary-butylquinone which comprises oxidizing Z-tertiarybutyl-4-methoxyphenol by treatment with concentrated sulfuric acid and vanadium pentoxide at a temperature of from about 10 to about +100 C.

8. A process for producing 2-tertiary-butylquinone which comprises oxidizing Z-tertiarybutyl-l-methoxyphenol by treatment with concentrated sulfuric acid, vanadium pentoxide, and potassium chlorate at a temperature of from about 10 to about +100 C.

9. A process for producing Z-tertiary-butylquinone which comprises oxidizing 2-tertiarybutyll-methoxyphenol by treatment with concentrated sulfuric acid and sodium nitrite at a temperature of from about -10 to about +1o0 0.

10. A process for producing 2,5-di-tert-butylquinone which comprises oxidizing 2,5-di-tertbutyll-methoxyphenol by treatment with concentrated sulfuric acid and vanadium pentoxide at a temperature of from about 10 to about +100 C.

11. A process for producing 2,5-di-t-butylquinone which comprises oxidizing 2,5-di-tertbutyll-metho-xyphenol by treatment with concentrated sulfuric acid, vanadium pentoxide, and potassium chlorate at a temperature of from-about -l0 to about +100 C.

12. A process for producin 2,5-di-t-buty1- quinone which comprises oxidizing 2,5-di-tertbutyll-methoxyphenol by treatment with concentrated sulfuric acid and sodium nitrite at a temperature of from about -10 to about +100 C.

WILLIAM K. T. GLEIM. ALEXANDER GAYDASCI-I.

REFERENCES CITED The following references are of record in the file of this patent:

Fichter, Helv. Chim. Acta 7, 809-810 (1924). 

1. A PROCESS FOR PRODUCING A QUINONE HAVING A HYDROCARBON SUBSTITUENT ON THE QUINONE RING WHICH COMPRISES OXIDIZING A MONOETHER OF A HYDROQUINONE IN THE PRESENCE OF AN OXIDIZING AGENT SELECTED FROM THE GROUP CONSISTING OF ALKALI CHLORATE, VANADIUM PENTOXIDE, NITROUS ACID AND SODIUM NITRITE. 